package Exam.filter;

import Exam.pojo.User;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebFilter(filterName = "UserFilter",
        urlPatterns = "/user/*",
        dispatcherTypes = {DispatcherType.FORWARD,
                DispatcherType.REQUEST})
public class UserFilter implements Filter {
    public void destroy() {
    }

    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain)
            throws ServletException, IOException {
        HttpServletRequest request= (HttpServletRequest) req;
        HttpServletResponse response= (HttpServletResponse) resp;
        HttpSession session=request.getSession();
        User user= (User) session.getAttribute("user");
        if(user!=null){
            // 已登入
            chain.doFilter(req,resp);
        }else {
            // 没登入
            response.sendRedirect("/login.jsp");
        }
    }

    public void init(FilterConfig config) throws ServletException {

    }
}
